// -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
/*
 * Copyright 2010 ZXing authors All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <zxing/pdf417/PDF417Reader.h>
#include <zxing/pdf417/detector/Detector.h>

using zxing::Ref;
using zxing::Result;
using zxing::BitMatrix;
using zxing::pdf417::PDF417Reader;
using zxing::pdf417::detector::Detector;

// VC++
using zxing::ArrayRef;
using zxing::BinaryBitmap;
using zxing::DecodeHints;

Ref<Result> PDF417Reader::decode(Ref<BinaryBitmap> image, DecodeHints hints) {
    Ref<DecoderResult> decoderResult;
    /* 2012-05-30 hfn C++ DecodeHintType does not yet know a type "PURE_BARCODE", */
    /* therefore skip this for now, todo: may be add this type later */
    /*
      if (!hints.isEmpty() && hints.containsKey(DecodeHintType.PURE_BARCODE)) {
      BitMatrix bits = extractPureBits(image.getBlackMatrix());
      decoderResult = decoder.decode(bits);
      points = NO_POINTS;
      } else {
    */
    Detector detector(image);
    Ref<DetectorResult> detectorResult = detector.detect(
            hints); /* 2012-09-17 hints ("try_harder") */
    ArrayRef<Ref<ResultPoint> > points(detectorResult->getPoints());

    if (!hints.isEmpty()) {
        Ref<ResultPointCallback> rpcb = hints.getResultPointCallback();
        /* .get(DecodeHintType.NEED_RESULT_POINT_CALLBACK); */
        if (rpcb != NULL) {
            for (int i = 0; i < points->size(); i++) {
                rpcb->foundPossibleResultPoint(*points[i]);
            }
        }
    }
    decoderResult = decoder.decode(detectorResult->getBits(), hints);
    /*
      }
    */
    Ref<Result> r(new Result(decoderResult->getText(), decoderResult->getRawBytes(), points,
                             BarcodeFormat::PDF_417));
    return r;
}

void PDF417Reader::reset() {
    // do nothing
}

Ref<BitMatrix> PDF417Reader::extractPureBits(Ref<BitMatrix> image) {
    ArrayRef<int> leftTopBlack = image->getTopLeftOnBit();
    ArrayRef<int> rightBottomBlack = image->getBottomRightOnBit();
    /* see BitMatrix::getTopLeftOnBit etc.:
       if (leftTopBlack == null || rightBottomBlack == null) {
       throw NotFoundException.getNotFoundInstance();
       } */

    int nModuleSize = moduleSize(leftTopBlack, image);

    int top = leftTopBlack[1];
    int bottom = rightBottomBlack[1];
    int left = findPatternStart(leftTopBlack[0], top, image);
    int right = findPatternEnd(leftTopBlack[0], top, image);

    int matrixWidth = (right - left + 1) / nModuleSize;
    int matrixHeight = (bottom - top + 1) / nModuleSize;
    if (matrixWidth <= 0 || matrixHeight <= 0) {
        throw NotFoundException("PDF417Reader::extractPureBits: no matrix found!");
    }

    // Push in the "border" by half the module width so that we start
    // sampling in the middle of the module. Just in case the image is a
    // little off, this will help recover.
    int nudge = nModuleSize >> 1;
    top += nudge;
    left += nudge;

    // Now just read off the bits
    Ref<BitMatrix> bits(new BitMatrix(matrixWidth, matrixHeight));
    for (int y = 0; y < matrixHeight; y++) {
        int iOffset = top + y * nModuleSize;
        for (int x = 0; x < matrixWidth; x++) {
            if (image->get(left + x * nModuleSize, iOffset)) {
                bits->set(x, y);
            }
        }
    }
    return bits;
}

int PDF417Reader::moduleSize(ArrayRef<int> leftTopBlack, Ref<BitMatrix> image) {
    int x = leftTopBlack[0];
    int y = leftTopBlack[1];
    int width = image->getWidth();
    while (x < width && image->get(x, y)) {
        x++;
    }
    if (x == width) {
        throw NotFoundException("PDF417Reader::moduleSize: not found!");
    }

    int moduleSize = (int) (((unsigned) (x - leftTopBlack[0])) >>
                            3); // We've crossed left first bar, which is 8x
    if (moduleSize == 0) {
        throw NotFoundException("PDF417Reader::moduleSize: is zero!");
    }

    return moduleSize;
}

int PDF417Reader::findPatternStart(int x, int y, Ref<BitMatrix> image) {
    int width = image->getWidth();
    int start = x;
    // start should be on black
    int transitions = 0;
    bool black = true;
    while (start < width - 1 && transitions < 8) {
        start++;
        bool newBlack = image->get(start, y);
        if (black != newBlack) {
            transitions++;
        }
        black = newBlack;
    }
    if (start == width - 1) {
        throw NotFoundException("PDF417Reader::findPatternStart: no pattern start found!");
    }
    return start;
}

int PDF417Reader::findPatternEnd(int x, int y, Ref<BitMatrix> image) {
    int width = image->getWidth();
    int end = width - 1;
    // end should be on black
    while (end > x && !image->get(end, y)) {
        end--;
    }
    int transitions = 0;
    bool black = true;
    while (end > x && transitions < 9) {
        end--;
        bool newBlack = image->get(end, y);
        if (black != newBlack) {
            transitions++;
        }
        black = newBlack;
    }
    if (end == x) {
        throw NotFoundException("PDF417Reader::findPatternEnd: no pattern end found!");
    }
    return end;
}
